Gut commensal bacterium

The term gut commensal bacteria refers collectively to non-pathogenic bacterial species that inhabit the human gastrointestinal tract. These bacteria play essential roles in digestion, nutrient synthesis (including amino acids like methionine), maintenance of mucosal immunity and integrity, colonization resistance against pathogens through competition and metabolite production, and modulation of host immune responses. The relationship between humans and these microbes is often mutualistic rather than strictly neutral. Alterations in their populations are associated with various diseases including inflammation-related conditions, gastrointestinal disorders such as constipation, and even cancer progression via effects on immune regulation. However, “gut commensal bacteria” is not a single molecular entity but an ecological category encompassing many different bacterial taxa predominantly from phyla such as Firmicutes and Bacteroidetes.

Other names

Commensal gut bacteriumCommensal bacteria of the gutIntestinal commensal bacteriumGut microbiota (inaccurate, as this refers to the whole community)